Is this the correct OCV method to transform two 2D points to one 3D?

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There's a moving object whose imagePoints I identity at two times with two MS LifeCams on my Windows 7 PC in MSVSC++. I want to determine the distance between those two 3D points. The steps I'm using are shown. I included almost no detail since now I want to just learn if I'm using the right OpenCV 2.3.1 functions.

1. calibrateCamera for each camera

     output: cameraMatrix and distCoeffs for each camera
   

2. simpleBlobDetect once for each camera at two times

     output: point 1 (cam1x1, cam1y1) (cam2x1, cam2y1)
     output: point 2 (cam1x2, cam1y2) (cam2x2, cam2y2)
   

3. stereoCalibrate

     output: R, T, E, & F
   

4. stereoRectify

     this doesn't actually rectify any images but produces R1,R2,P1 & P2 so it can be done
   

5. undistortPoints

     output: vector of Point2f objects in rectified image
   

6. perspectiveTransform

   output: vector of Point3f objects
   

From 30k feet are these the correct steps?

Thanks. Charles